Refrigeration unit

ABSTRACT

The invention relates to a refrigeration unit ( 10 ). The unit includes a refrigeration zone ( 20 ) for receiving an item or items to be refrigerated, and dispensing means ( 24 ) oriented relative to the refrigeration zone so as to enable dispensing of a working fluid into the refrigeration zone. The unit further includes catchment means which are arranged relative to the refrigeration zone so as to collect the working fluid after it has been dispensed into the refrigeration zone. The unit includes also cooling means ( 38 ) for cooling the working fluid in use. The invention extends to a method of refrigerating an item.

THIS INVENTION relates to refrigeration. It more particularly relates toa method of refrigerating an item, and to a refrigeration unit.

The Applicant is of the opinion that the invention will particularlyadvantageously be applicable to rapid refrigeration of items, and thatapplication will particularly be bome in mind for purposes of thisspecification. Naturally, however, the invention may be used in otherapplications.

In accordance with one aspect of the invention, there is provided amethod of refrigerating an item, which method includes

-   -   cooling a working fluid to a temperature lower than that of an        item to be refrigerated;    -   dispensing the cooled working fluid onto the item thereby, on        account of heat exchange between the working fluid and the item,        extracting heat from the item to refrigerate the item; and    -   collecting the dispensed working fluid for re-use.

The working fluid may be cooled to a predetermined temperature and maybe continuously dispensed onto the item for a time required torefrigerate the item to a desired temperature.

Dispensing of the working fluid onto the item may be by spraying it ontothe item.

Collection of the dispensed working fluid may be by collecting it underthe influence of gravity by means of catchment means.

The method may be executed in a substantially enclosed refrigerationzone with walls defining the enclosed zone forming the catchment means.

Cooling of the working fluid may be by bringing it into direct contactwith an evaporator forming part of a closed-loop refrigeration system.

In accordance with another aspect of the invention, there is provided arefrigeration unit which includes

-   -   a refrigeration zone for receiving an item or items to be        refrigerated;    -   dispensing means oriented relative to the refrigeration zone so        as to enable dispensing of a working fluid into the        refrigeration zone; and    -   catchment means arranged relative to the refrigeration zone so        as to collect the working fluid after it has been dispensed into        the refrigeration zone.

The refrigeration unit may include cooling means for cooling the workingfluid in use.

The refrigeration unit may include a first enclosed compartment, havinga sealingly closeable access opening, within which the refrigerationzone is defined, with walls of the compartment forming the catchmentmeans.

The dispensing means may include spraying nozzles located within thefirst compartment. The spraying nozzles may be mounted on or proximateat least some of the walls of the compartment and may be oriented todirect the working fluid away from their associated walls.

A floor or bottom wall of the first compartment may be apertured to passworking fluid flowing operatively downwardly under the influence ofgravity, thereby to direct collected working fluid in use.

The refrigeration unit may include a second enclosed compartment withinwhich the working fluid is received and cooled in use.

The second compartment may be in fluid flow communication with the firstcompartment so as to receive the collected working fluid passing throughthe aperture or apertures in the bottom wall of the first compartment.

The second compartment may be positioned below the first compartment topermit collected working fluid to flow from the first compartment intothe second compartment under the influence of gravity.

The cooling means may include a primary, closed-loop refrigerationsystem having an operatively interconnected condenser, expansion means,evaporator, and compressor with associated motor, and having anassociated refrigerant, with the evaporator being positioned in thesecond compartment so as to extract heat from the working fluid in thesecond compartment in use, thereby to cool the working fluid.

The refrigeration unit may include a secondary, closed-looprefrigeration system substantially similar to the primary, closed-looprefrigeration system, with an evaporator of the secondary refrigerationsystem in heat exchange relationship with the condenser of the primaryrefrigeration system thereby to extract heat from the condenser and,hence in use, to enable cooling of the primary refrigeration systemrefrigerant and, accordingly, the working fluid to lower temperatures.

The refrigeration unit may include a portable housing which houses thecomponents of the or each refrigeration system and within which thefirst compartment and the second compartment are defined.

The refrigeration unit may include a pump having its inlet in fluid flowcommunication with the second compartment and its outlet in fluid flowcommunication with the spraying nozzles. The pump may be activatable soas to pump the working fluid from the second compartment to the sprayingnozzles for dispension thereof in use.

The refrigeration unit may include circulation means for circulating theworking fluid in the second compartment in use.

At least the first and the second compartments may be thermallyinsulated.

The invention is now described, by way of example, with reference to theaccompanying diagrammatic drawings.

In the drawings:

FIG. 1 shows a schematic layout of a refrigeration unit in accordancewith the invention;

FIG. 2 shows, in part-sectional front view, a refrigeration unit inaccordance with the invention; and

FIG. 3 shows, in part-sectional top view taken at III-III in FIG. 2, therefrigeration unit in accordance with the invention.

With reference to the drawings, a refrigeration unit in accordance withthe invention is generally indicated by reference numeral 10. The device10 includes a parallelepipedal housing 12 defining a firstparallelepipedal compartment 14, a second parallelepipedal compartment16 which is slightly smaller than and located operatively below thefirst compartment 14, and a third parallelepipedal compartment 18located operatively alongside the compartments 14, 16.

The first compartment 14 defines a refrigeration zone 20 within which anitem or items to be refrigerated is/are receivable. The secondcompartment 16 defines a reservoir within which a working fluid, e.g.ethanol, which is used to refrigerate the item or items, is receivableand coolable to a temperature below that of the item or items to berefrigerated.

The unit 10 further includes dispensing means, generally indicated byreference numeral 24, oriented relative to the refrigeration zone 20 soas to enable dispensing of the working fluid into the refrigeration zone20.

The first compartment 14 is defined by a top wall 26, a floor or bottomwall 28 spaced from the top wall 26, opposing side walls 30, 32, a rearwall 34 and an operatively front wall defined by a door 36. The door 36is hingeably connected to the housing 12 (the hinges are not shown) andwhen in the open position allows access into the refrigeration zone 20.When in the closed position, the door 36 seals off the compartment 14.The unit 10 may include a latch mechanism (not shown) for sealinglyretaining the door 36 in the closed position.

The respective walls defining the first compartment 14, also definecatchment means for catching or collecting dispensed working fluid.

The side walls 30,32 and the rear wall 34 extend operatively downwardlyto define rear and side walls of the second compartment or reservoir 16.The second compartment is further defined by a front wall (not visible)and a bottom wall or floor 35. Also, with the exception of the side wall37, walls defining the third compartment 18 are mere extensions of thewalls defining the first and second compartments 14, 16.

The respective walls defining the first and second compartments 14, 16are thermally insulated so as to prevent heat exchange between theinterior of the compartments 14, 16 and their surroundings.

The unit 10 further includes cooling means in the form of a primary,closed-loop refrigeration system generally indicated by referencenumeral 38.

The dispensing means 24 is constituted by a first array of sprayingnozzles 40 and a second array of spraying nozzles 42. The first array ofspraying nozzles 40 is mounted on a panel 41 which is secured inside thecompartment 40 to an inner face 26.1 of the top wall 26. The panel 41 isof a size substantially similar to that of the inner face 26.1 of thetop wall 26 and, if desired, may be embedded into the top wall 26. It isto be appreciated, that the nozzles 40, need not necessarily be mountedon a panel which then, in turn, is mounted to the wall 26 of thecompartment 14, but the nozzles 40, can instead be mounted on the wall26. The second array of spraying nozzles 42 is mounted on an inner face28.1 of the bottom wall 28.

The nozzles 42 can, however, also be mounted on a panel which then, inturn, is mounted to the bottom wall 28.

The bottom wall 28 includes an array of circular apertures 44 spacedinbetween the nozzles 42. If the nozzles 42 are mounted on a panel, thepanel will include circular apertures which are in register with theapertures 44. These apertures 44 provide fluid flow communicationbetween the first compartment 14 and the second compartment or reservoir16. In FIG. 1 the fluid flow communication provided by the apertures 44is indicated by a fluid flow communication connection 46. The purpose offluid flow communication between the first compartment 14 and the secondcompartment or reservoir 16 will become more apparent hereinafter.

The unit 10 further includes a pump 48 having an inlet thereof in fluidflow communication with the second compartment or reservoir 16, and anoutlet thereof in fluid flow communication with the respective nozzles40, 42. The pump 48 has an associated motor (not shown) for driving itin use. In the embodiment shown, however, the pump 48 is located withinthe reservoir 22. The fluid flow communication between the pump 48 andthe respective nozzles 40, 42 is provided by a conduit network,generally indicated by reference numeral 50, and constituted by aconduit 50.1 providing fluid flow communication with the nozzles 42 anda conduit 50.2 providing fluid flow communication with the nozzles 40.

In a variant embodiment (not shown), instead of having a hingeable door36 providing access into the first compartment 14, the top wall 26 ofthe first compartment 14 may be a sealingly seated, removable lid. Inthis embodiment, which will typically be used in smaller applicationssuch as portable refrigeration units, the nozzles 40 will typically bemounted on an underface of the lid, or the panel 41 will be an integralpart of the lid. Here, the lid will include a fluid flow connectorwhich, upon closure of the lid will be aligned and sealingly engagedwith the conduit 50.2.

Circulation means in the form of a circulation pump 52 is providedwithin the reservoir 22, in use, to circulate the working fluid withinthe reservoir 22 to get in proper contact with the evaporator 48 coolingthe fluid and evenly to spread the temperature in the working fluid. Thepump 52 also has an associated motor (not shown) for driving it in use.

The primary refrigeration system 38 includes a condenser 54, an expanderor expansion valve 56, an evaporator 58 and a compressor 60, whichrespectively are in fluid flow communication via a conduit network,generally indicated by reference numeral 62, to form a closed-loopsystem. The unit 10 includes also a pump (not shown) for driving thecompressor in use. The condenser 54, the expander or expansion valve 56,and the compressor 60 are all located within the third compartment 18.The evaporator 58 is located within the second compartment or reservoir16. The primary refrigeration system 38 includes also a suitablerefrigerant which is circulated within the closed-loop system.

In use, the compressor 60 compresses the refrigerant, which at thispoint is in vapour form, and feeds it via a conduit 62.1 to thecondenser 54 where it is condensed. From the condenser 54 therefrigerant, which is now in liquid form, flows to the expansion valve56 via a conduit 62.2. In the expansion valve 56, the refrigerant isexpanded and from there flows to the evaporator 58, where it isevaporated. On account of the nature of the refrigerant, the evaporationis an endothermic process and heat is thus absorbed from the workingfluid within the first compartment or reservoir 16 upon evaporation ofthe refrigerant. From the evaporator 58 the refrigerant flows, via aconduit 62.4, back to the compressor 60.

In use, the working fluid in the second compartment or reservoir 16 iscooled as hereinbefore described, an item or items to be refrigerated islocated within the first compartment 14, and the cooled working fluid 16is dispensed, via the nozzles 40, 42, onto the item or items thereby torefrigerate it. Dispensing of the working fluid onto the item or itemsis effected by actuation of the pump 48. The device 10 will include alsoan actuator such as a switch, or the like for actuating operation of thepump 48. Upon actuation of the pump 48, it pumps working fluid from thesecond compartment or reservoir 16 via the conduits 50.1, 50.2 to therespective nozzles 40, 42 by means of which it is dispensed, in dropletform, onto the item or items within the first compartment 14.

The working fluid will typically be cooled to a predeterminedtemperature and will then be continuously dispensed onto an item oritems to be refrigerated for a time required to refrigerate the item oritems to a desired temperature. Working fluid dispensed into the firstcompartment 14 is retained within the first compartment by means of itswalls 26, 28, 30, 32, 34 and its door 36. After being dispensed, theworking fluid flows toward the floor or bottom wall 28 under gravity andpasses through the apertures 44 which, in turn, leads into the secondcompartment or reservoir 16. The dispensed working fluid is thuscollected for re-use.

The device 10 shown in FIG. 1 includes also a secondary closed-looprefrigeration system, shown in dotted, generally indicated by referencenumeral 64. The secondary refrigeration system 64 is substantiallysimilar to the primary refrigeration system 38. It includes a condenser66, an expansion valve 68, an evaporator 70, and a compressor 72 withits associated motor, which respectively are in fluid flow communicationvia a conduit network generally indicated by reference numeral 74.Respective sections of the network 74 are indicated by referencenumerals 74.1, 74.2, 74.3, 74.4.

The secondary refrigeration system 64 functions similarly to the primaryrefrigeration system 38. Here, however, the evaporator 70 is in heatexchange relationship with the condenser 54 of the primary refrigerationsystem 38 so as, in use, to extract heat from the condenser 54.Preferably, the evaporator 70 and the condenser 54 are located within aninsulated casing 76. The primary and the secondary refrigeration systemsare thus in combined or cascaded formation. This combined or cascadedrefrigeration system enables the primary refrigeration systemrefrigerant and, hence, the working fluid to be cooled to lowertemperatures.

It is an advantage of this invention that it provides a refrigerationdevice which enables rapid refrigeration of an item or items torelatively low temperatures. It is a further advantage that the workingfluid used in the device can be collected and re-used.

1. A method of refrigerating an item, which method includes cooling aworking fluid to a temperature lower than that of an item to berefrigerated; dispensing the cooled working fluid onto the item thereby,on account of heat exchange between the working fluid and the item,extracting heat from the item to refrigerate the item; and collectingthe dispensed working fluid for re-use.
 2. A method as claimed in claim1, in which the working fluid is cooled to a predetermined temperatureand is continuously dispensed onto the item for a time required torefrigerate the item to a desired temperature.
 3. A method as claimed inclaim 1 or claim 2, in which dispensing of the working fluid onto theitem is by spraying it onto the item.
 4. A method as claimed in any oneof the preceding claims, in which collection of the dispensed workingfluid is by collecting it under the influence of gravity by means ofcatchment means.
 5. A method as claimed in claim 4, which is executed ina substantially enclosed refrigeration zone with walls defining theenclosed zone forming the catchment means.
 6. A method as claimed in anyone of the preceding claims, in which cooling of the working fluid is bybringing it into direct contact with an evaporator forming part of aclosed-loop refrigeration system.
 7. A refrigeration unit which includesa refrigeration zone for receiving an item or items to be refrigerated;dispensing means oriented relative to the refrigeration zone so as toenable dispensing of a working fluid into the refrigeration zone; andcatchment means arranged relative to the refrigeration zone so as tocollect the working fluid after it has been dispensed into therefrigeration zone.
 8. A unit as claimed in claim 7, which includescooling means for cooling the working fluid in use.
 9. A unit as claimedin claim 8, which includes a first enclosed compartment, having asealingly closeable access opening, within which the refrigeration zoneis defined, with walls of the compartment forming the catchment means.10. A unit as claimed in claim 9, in which the dispensing means includesspraying nozzles located within the first compartment, the sprayingnozzles being mounted on or proximate at least some of the walls of thecompartment and oriented to direct the working fluid away from theirassociated walls.
 11. A unit as claimed in claim 9 or claim 10, in whicha floor or bottom wall of the first compartment is apertured to passworking fluid flowing operatively downwardly under the influence ofgravity, thereby to direct collected working fluid in use.
 12. A unit asclaimed in claim 10 or claim 11 inclusive, which includes a secondenclosed compartment within which the working fluid is received andcooled in use, the second compartment being in fluid flow communicationwith the first compartment so as to receive the collected working fluidpassing through the aperture or apertures in the bottom wall of thefirst compartment.
 13. A refrigeration unit as claimed in claim 12, inwhich the second compartment is positioned below the first compartmentto permit collected working fluid to flow from the first compartmentinto the second compartment under the influence of gravity.
 14. Arefrigeration unit as claimed in claim 12 or claim 13, in which thecooling means includes a primary, closed-loop refrigeration systemhaving an operatively interconnected condenser, expansion means,evaporator, and compressor with associated motor, and having anassociated refrigerant, with the evaporator being positioned in thesecond compartment so as to extract heat from the working fluid in thesecond compartment in use, thereby to cool the working fluid.
 15. Arefrigeration unit as claimed in claim 14, which includes a secondary,closed-loop refrigeration system substantially similar to the primary,closed-loop refrigeration system, with an evaporator of the secondaryrefrigeration system in heat exchange relationship with the condenser ofthe primary refrigeration system thereby to extract heat from thecondenser and, hence in use, to enable cooling of the primaryrefrigeration system refrigerant and, accordingly, the working fluid tolower temperatures.
 16. A refrigeration unit as claimed in claim 14 orclaim 15, which includes a portable housing which houses the componentsof the or each refrigeration system and within which the firstcompartment and the second compartment are defined.
 17. A refrigerationunit as claimed in any one of claims 12 to 16 inclusive, which includesa pump having its inlet in fluid flow communication with the secondcompartment and its outlet in fluid flow communication with the sprayingnozzles, the pump being activatable so as to pump the working fluid fromthe second compartment to the spraying nozzles for dispension thereof inuse.
 18. A refrigeration unit as claimed in any one of claims 12 to 17inclusive, which includes circulation means for circulating the workingfluid in the second compartment in use.
 19. A refrigeration unit asclaimed in any one of claims 12 to 18 inclusive, in which at least thefirst and the second compartments are thermally insulated.
 20. A methodas claimed in claim 1, substantially as herein described andillustrated.
 21. A refrigeration unit as claimed in claim 7,substantially as herein described and illustrated.
 22. A new method, ora new refrigeration unit, substantially as herein described.